This invention relates to vacuum cleaners, and more particularly to those whose primary function is the cleansing of submerged surfaces. The term "submerged surfaces" in the present specification is utilized to denote either the side walls, or the floor of a tank structure containing a liquid.
A tank, such as a swimming pool, has a tendency to accumulate debri when exposed to outside conditions. This debri may be found in various forms. For example, the debri may consist of leaves and other organic matter that often settle to the bottom of a pool thereby creating both an unsanitary and unsightly condition. Debri may also consist of small pebbles and other hardened matter which similarly settles to the bottom of a pool, or tank structure. Even smaller particulate matter, such as common dirt, when mixed with oil, create a film upon these submerged surfaces. This film is not readily removable with a mere suction device, but often necessitates the use of a scrubbing element in conjunction with a suction element.
Because of the inability to reach certain areas in the pool structure, it is desirable to have a device which accomplishes the same cleaning action in either a forward or rearward direction of movement.
As a result of the various size debri and matter found on the surfaces discussed above, it is similarly desirable to have a vacuum cleaner that has the ability to remove the larger matter prior to the scrubbing of the wall, and then to remove the attached film. By removing the larger particles first, it is possible to achieve greater cleaning efficiency.
Various attempts have been made to accomplish the desired cleaning efficiency necessary to economically maintain the required sanitary level in a swimming pool. Prior devices illustrate either a suction device or a brush-and-suction device, however, as the above discussion illustrates, the cleaning of underwater surfaces consists of being able to perform a multitude of functions almost simultaneously.
Prior devices also do not illustrate the ability to cleanse efficiently in either direction of movement. A greater number of moving parts have been required to achieve this desirable result.
Additionally, prior devices do not utilize the viscosity of the fluid, through which they pass, to aid in the scrubbing action required to cleanse the submerged walls of the film that becomes attached after a very short period of time. Previously, this has been unsuccessfully accomplished by a mere row of brushes, which do not obtain the required cleansing efficiency. Attempts to solve this problem have manifested themselves in much heavier and cumbersome devices, which nonetheless fail to achieve an acceptable cleaning level.